Scaffold



2 Sheets-Sheet 1. R. 0. SEAT. SGAPPOLD.

(No Model.)

No. 415,223. Patented Nov. 19, 1889. I

um m Wmhingion. u. c.

2 Sheets-Sheet 2.

(No Model.)

B. O. SEAT. SGAFFOLD.

No. 415,223. PatentedNov. 19, 1889.

lWi/L'meooea UNITED STATES.

PATENT OFFICE.

ROBERT O. SEAT, OF CARLYLE, ILLINOIS.

SCAFFOLD.

SPECIFICATION forming part of Letters Patent No. 415,223, dated November19, 1889.

Application filed July 15, 1889. Serial No. 317,517. (No model.)

To aZZ whom, it may concern.-

Be it known that 1, ROBERT O. SEAT,a citizen of the United States ofAmerica, residing at Carlyle,in the county of Clinton and State ofIllinois, have invented certain new and useful Improvements inScaffolds, of which the following is a specification, reference beinghad therein to the accompanying drawings.

This invention relates to certain new and useful improvements inscaffolds; and it has for its objects to provide a device of thischaracter which shall be simple in its construction, capable ofadjustment with ease either with or without its load, and which shall bestrong and durable and very efficient in use.

The novelty resides in the peculiar combinations and the construction,arrrangernent, and adaptation of parts, all as more fully hereinafterdescribed,shown in the drawings, and then particularly pointed out inthe appended claims.

The invention is clearly illustrated in the accompanying drawings,which, with the letters of reference marked thereon,form a part of thisspecification, and in which Figure 1 is a perspective view of a scaffoldconstructed in accordance with my invention, with the upper ends of theposts broken away. Fig. 2 is a side elevation thereof without theextensions of the posts and hoisting or elevating levers. Fig. 3 is avertical sectional detail, which will be more particularly hereinafterreferred to by letters of reference. Fig. 4: is a perspective View ofone of the supportin g-arins detached.

Referring now to the details of the drawings by letter, A designates theuprights or posts, which are preferably rectangular in cross-section,although other forms may be employed, if desired. The lower ends ofthese posts are braced in any suitable manner-as, for instance, by meansof the inclined braces a, and preferably resting on the base B, to whichthe lower ends of the braces a are secured. These posts are provided atsuitable distances apart with the transverse rectangular holes 1),extending through the posts for a purpose hereinafter set forth. Theseposts are made extensible in length in the following manner: The upperends of the posts are halved out, as shown at c, and the extensionpieces0 are also halved out at their lower ends and these halved-out endsfitted together, as shown in Fig. 1, and are thus held b y means of thebolts d, which pass through suitable holes in the lapped ends, the headsof the bolts being seated in recesses in the posts and extension-piecesand nuts 6 screwed 0n the opposite ends of the bolts, the nuts beingseated in correspondingly-sh'aped recesses f in the posts andextension-pieces to prevent turning of the same, the two bolts in eachpost and extension-piece being arranged reversely, as shown in Fig.3that is, the head on one bolt is on the side of the post opposite thehead on the other bolt. This gives greater security against pulling outof the bolts.

D is the platform, formed of suitable material and of the desiredlength, having at its ends recesses g to receive the posts, and near thecenter of its length with apertures h, through which pass the uprightlifting arms or levers, as will be hereinafter described.

E are the platform-supporting arms, made easily removable and designedto work in the holes I) and to support the platform, as will be readilyunderstood from the description hereinafter given. To the side of theposts are the uprights F, having at their upper ends a recess t' and ahole j.

G are the liftinglevers, having one end pivoted to the uprights F bymeans of a pin passed through the end of the lever and through the holein said uprights.

H are the upright lifting arms or levers pivoted at their lower ends, asat k, to the lifting-levers G, near the center of the length of thelatter, and provided at suitable distances apart with transverseopenings Z, through which are passed the pins on to engage the underside of the platform, as shown. These upright lifting arms or levers aremade extensible in the same manner as the posts.

The operation is simple and is as follows: With the parts in theposition in which they are shown in Fig. 1, with a pin m passed throughone of the openings in'the upright arms beneath the platform, by liftingon the lifting-lever G and bringing it into the position shown at theleft of Fig. 2 the opposite end of the platform will be raised, as shownin the latter figure, when the attendant on the platform removes thecross supportingarm E from its hole in the post and places it in thenext higher hole. The other end is then raised in the same manner, theattendant removing the supporting-arms and placing them in higher holesas the platform is raised. The opposite ends of the platform may beraised alternately, or both ends may be raised simultaneously, as may bedesired. When both ends are raised simultaneously, there will betwooperators on the grou ndone at each leveras will be readilyunderstood. After removing the supportingarms and placing them in higherholes the attendant then removes the pins from the upright arms andplaces them in higher holes,when the op-- eration is repeated.

At each end of the platform I provide vertical holes 02, through whichare passed. the pins 0, which bear against the outer face of thesupporting-arms and prevent endwise movement of the platform, said pinsbeing readily removable when desired.

What I claim as new is- 1. The combination, with the posts and platformmovable vertically on said posts, of the lifting-levers pivoted near thelower ends of said posts, the upright arms connected with the levers,and the removable pins and supporting-arms, substantially as shown anddescribed.

2. The combination, with the extensible posts and the platform movableon said posts,

platform, of the lifting-levers, the upright arms, the supporting-arms,and the vertical pins passed through, openings in the ends of theplatform and bearing against the outer faces of the supporting-arms,substantially as shown and described, and for the purpose specified. I

In testimony whereof I affix my sign ature 1n presence of two witnesses.

hi ROBERT o. SEAT.

' mark Attest:

PORTER W. BROWN, JOHN J. MCGAFFIGAN.

